Accidental needle stick injuries continue to represent a significant percentage of the injuries which occur in the medical field. Such injuries generally occur when an individual such as a physician or nurse attempts to insert a hypodermic needle into its sheath after use. The opening in these conventional elongated needle sheaths is relatively small, and in maneuvering the needle for insertion thereinto, unless an extreme degree of care is employed, the point of the needle can miss the opening and puncture the fingers of the individual who is holding the sheath. Further injuries from hypodermic needles occur when housekeeping personnel in a hospital or other medical facility remove the used hypodermic needles from waste containers in order to dispose of them. In these waste containers, the needles may have separated from their sheaths, leaving them exposed, and accordingly, subjecting the housekeepers to accidental puncture therefrom.
Accidental puncture by a hypodermic needle therefore represents a common and serious risk to all medical personnel. According to an article in the "American Journal of Medicine" dated April, 1981, needle stick injuries accounted for one-third of all work-related accidents, with 60% of all such injuries occurring with nursing personnel. Such injuries pose a serious health hazard to the affected individual. According to this same article, accidental puncture by a hypodermic needle can engender serious disease, including potentially fatal viral hepatitis. Further, blood or other bodily fluids infected with the deadly AIDS virus may be introduced into such a puncture wound via contaminated needles. Accordingly, inadvertent needle sticks subject medical personnel to the risk of contracting highly contagious diseases, including potentially fatal viral hepatitis and acquired immune deficiency syndrome (AIDS).
Because of the serious nature of this problem, there have been many attempts to protect medical personnel from the risks of such needle punctures. These attempts have taken the form of a relatively large number of devices which are intended to be used instead of or in conjuction with the conventional syringes. One such prior art device for preventing inadvertent needle punctures entails a cylindrical plastic guard that slides up and covers the end of the needle after it has been used. Once the guard locks into place, it cannot be retracted. However, this safety device of the prior art entails several disadvantages. The cylindrical guard, which is disposed on the shaft of then needle, is a substantial portion of a length of the needle itself. Accordingly, a relatively small portion of the needle projects from the cylindrical guard. This renders the needle more difficult to manipulate and to position owing to the encumbrance of the guard on the shaft of the needle, and the obstruction of the view of the needle tip by the lengthy cylindrical guard. Further, hypodermic needles comprising such cylindrical guards are highly priced compared to conventional needles.
Pedicano et al, U.S. Pat. No. 4,610,667, discloses one form of known safety device. In this case, there is provided a disposable needle sheath which includes an elongated sleeve with a closed end and a funnel-shaped receiving guide at its open end. This device also includes a cap for sealing the open end after the needle has been inserted into the sleeve. In a preferred form of this device, as shown in FIGS. 6-12 thereof, means are provided within the sleeve 12 for grasping the needle hub therein. These can take the form of the needle locking threads 50 of FIGS. 6 and 7 and the gripping arms 58 of FIGS. 9 and 10. In each case, however, the needle remains accessible for removal from the open end of the sleeve. Furthermore, these devices are not usable with the conventional needle sheaths presently being utilized, but are intended to replace same.
There are also a large number of protective devices and packages which are intended to substantially encase a needle or a needle contained in a needle sheath. These include Hamilton, U.S. Pat. No. 3,021,442; Danish Pat. No. 133,797; German Pat. No. 1,240,228; Hamilton, U.S. Pat. No. 3,367,488; and Sampson, U.S. Pat. No. 4,425,120.
Mayer, U.S. Pat. No. 4,485,918, discloses apparatus for disposing of needles, including a funnel-like sheath 16 therein. The resheathed needle can then be disposed of in a container 40 having a slit aperture 43 for stripping the sheathed needle from the syringe spigot 20.
Additional patents include disclosures of protective sheaths which can be mounted on a syringe. For example, Nitshke, U.S. Pat. No. 4,232,669, discloses a sheath 16 having a separate cap 68 for maintaining on syringe 14 by functionally engaging syringe hub 26. Also, Brown, U.S. Pat. No. 3,677,247, discloses a syringe package 10 which includes a barrel cap 30 and a needle sheath 36. A frangible sheath is shown in Stevens, U.S. Pat. No. 3,073,307, and a separate sheath element is shown in Smith, U.S. Pat. No. 3,434,473.
Jagger et al, U.S. Pat. No. 4,592,744, discloses a self-resheathing needle assembly in which the syringe is removed from case 10 after use, and the needle assembly 30 is severed therefrom by contact with projections 52. Cooper, U.S. Pat. No. 4,629,453, discloses a protective cap 10 which includes a radially extending flange 2 to protect against misallignment of the needle, and Frist et al, U.S. Pat. No. 4,573,975, discloses a protective shield 14 which can be folded as in FIG. 3 thereof, and which is intended to protect the user's hand upon entry of the needle.
With all of these prior art devices, and in fact many more, none have been made available which can simply and easily be incorporated into conventional syringes and needle sheaths so as to effectively protect the users thereof. Furthermore, none of these devices can be mounted directly onto the forward end of a conventional syringe and also assist in the application of a conventional needle and needle sheath onto the syringe, insure proper needle application, and/or later act as a protective guard for the user when applying the used needle to the needle sheath.
Furthermore, none of these devices can be used to help insure that the needle itself is properly applied to the syringe. Finally, none of these prior art devices can be used to capture the needle hub therein so as to block extraction of the used needle from a needle sheath so as to facilitate disposal thereof.